I decided to put together a few lessons on pronunciation and intonation for my site, and need your comments/advice. I've only taught Japanese learners of English, and so am very familiar with their problem areas in speaking. But what is it like with other learners? Specifically:

1. Are there specific sounds difficult to pronounce because of the learner's L1?

2. Are there sound pairs that cause problems? For example, Japanese people have a lot of trouble with "b" and "v," or "l" and "r."

﻿Therere many sound pairs that cause problem for the Chinese, Korean, Spanish, Vietnamese, Hindi/Tamil, Arabic and Iranian/Farsi students in our area.

For example, consonant pair "b" & "v" seems to cause problem for Spanish & Hindi students & "l" and "r" for Korean students. Chinese students have problem with f/v & l/n. All students have problem with ﻿θ & ๐, ﻿I & i: , and r , just to name a few.

There is a lot of native language interference with most of my (adult) students. I bet you could find a native language that caused trouble with any similar sounds (voiced/voiceless pairs, close articulation, etc.)

In addition to what's already been mentioned,

Russians have trouble with e like in pet and a like in pat, and with w and v

Koreans and Filipinos have trouble with f and p

Cantonese speakers have trouble with s and sh

Spanish and Chinese speakers have trouble with s and z

Spanish speakers have trouble with sh and ch

(Not to mention the American English flap or tap sound in the middle of butter)